Conservative MPs will demand action to recognise marriage in the tax system by
allowing spouses to transfer their personal allowances.

Backbenchers have tabled an amendment to the Finance Bill that would allow spouses who do not work to transfer their unused personal allowance to a working partner, cutting their tax bill. The amendment could be debated in the Commons as soon as today.

The move will put pressure on David Cameron to deliver on a Conservative manifesto pledge to introduce the measure. So far, 10 Conservative MPs have backed the amendment, which was tabled by Fiona Bruce, the MP for Congleton.

The Liberal Democrats have threatened to oppose the measure, insisting their policy of raising the personal allowance to £10,000 must take priority, and Tory backbenchers want Mr Cameron to overrule his junior partners.

“This is about putting down a marker, making sure that the policy isn’t forgotten,” said a supporter of the measure. Senior Conservatives are keen to push ahead with the marriage tax break, and Treasury officials are understood to be studying ways to implement the policy.

But one Tory minister said it would help to “keep the issue on the agenda” within the Coalition.